I’m not a huge fan of upscalers. Many of them sound sterile, overly hyped, and artificial. More importantly, they didn’t make the music sound any less digital. Most often than not- an unadulterated signal is best.

Well, that was until I heard the Chord Electronics Blu Mk. 2 M Scaler a few years ago. In summary, there were no hints of digital while playing music files with this upscaler.

A quick comparison between Roon’s software-based upscaler and the Blu Mk.2 – and you’ll hear what I mean. There’s just more texture, body, and shape to the music. Digital audio has never sounded so informative. Albeit, at a much larger price tag.

So, what exactly makes the M Scaler so special? First, let’s cover some basics on upsampling.

Why Upsampling Matters

With a Red Book recording (CDs), we have 44,100 samples per second at 16-bit resolution per sample. An analog waveform has an infinite number of samples. How shall we do the analog-to-digital conversion? That brings us to the Nyquist Theorem.

The Nyquist Sampling Theorem states that a perfectly bandlimited signal can be sampled and be reconstructed perfectly.

The thing is – a perfectly bandlimited signal doesn’t exist in the real world. Brick-wall and “gentle” filters aren’t perfect – and depending on the input frequencies, will still produce artifacts. Essentially, the theorem isn’t practical.

In this regard, the additional headroom of upsampling comes in handy. When done correctly, the benefits of upscaling are numerous – including the attenuation of artifacts, pre-ringing/echos, and aliasing.


As far as the actual interpolation, most upscalers simply “connect the dots” between sample points. Subsequently, generating points on those lines. On the other hand, the Hugo M Scaler essentially steps back – and takes a holistic look at the waveform. Both forwards and backward in time. Natural waveforms behave within certain bounds – and this approach leverages that fact.

Effectively, instead of using straight line approximation, it interpolates based on the actual waveform. This approach (theoretically) should perfectly reconstruct the original waveform – providing analog-like resolution, proper timbre, and accurate timing in transients.

As you know, the human ear error is very sensitive to timing errors. Consequently, in order to accomplish this, a powerful FPGA and a million lines of code were required. And that is the heart of the Hugo M Scaler.

The Chord Electronics Hugo M Scaler

The Chord Electronics Blu Mk.2 revolutionalized how audiophiles were listening to their digital library and CDs. Unfortunately, the Blu Mk.2 is prohibitively expensive for many (~$11,000 USD).

Rob Watts, Chord Electronic’s digital designer/consultant, wanted to get the M Scaler technology into more ears. He wanted a more compact version without compromises. Fast forward another year – and the Chord Electronics Hugo M Scaler was born. This time without a CD player – and in tabletop fashion.

The Hugo M Scaler works with any DAC with compatible inputs. You’ll be able to upscale your 44.1kHz/16-bit files to 705.6kHz/24-bit. In addition, it’s able to deliver a ridiculous 768 kHz/24-bit PCM signal in dual-BNC mode – with a compatible Chord Electronics DAC.

Please take a look at my review and this white paper for more details on the Watts Transient Aligned (WTA) filter M Scaler technology. I’ll be focusing primarily on listening tests.

Dual BNC (DBNC) Compatible Chord DACS:

  • Qutest
  • Hugo 2
  • Hugo TT 2
  • DAVE

In addition to a few other DACs, I’ll be going over listening impressions for all of these Chord Electronics DACs. I’ve had the Hugo M Scaler for many months and have taken notes over an enormous amount of equipment flux (different amps, cables, headphones, etc). I’m glad to report – the performance of the Hugo M Scaler was consistent throughout.

Chord Electronic DACs and Taps

DAC 641,024
Hugo 2 / Qutest49,152
TT 298,304
Blu Mk.2 / Hugo M Scaler1,015,808